Sources: Rand McNally (1898)
Miles of railroads in the United States, 1830-1893. Interstate Commerce
Commission (ICC), Statistics of Railways in the United States. BTS and Association
of American Railroads (AAR).
Note: A Class I railroad is a large rail operator. Data represent miles
of road owned (aggregate length of road, excluding yard tracks, sidings,
and parallel lines). Rail Track Mileage and Number of Class I Rail Carriers, United States,
1830-2012The evolution of rail transportation in the United States can be
conceptualized as a cycle composed phases of introduction,
rapid growth, maturity and rationalization.

Introduction (1830-1860). From modest beginnings and
untested technology, rail transportation emerged in the 1830s with
the construction of numerous local lines, dominantly
in the Northeast. By 1840, 3,000 miles of tracks were laid, but
rail transportation was still uncompetitive in regard to waterways
which had a wider coverage (e.g. Erie Canal, Mississippi). Many
of the first rail lines were actually
portage segments within the
canal system or routes aiming at complementing existing canals.
A set of independent feeder rail networks was also being established.
As the network extended, the Appalachian mountains were crossed
in the early 1850s and rail transportation was able to compete more
effectively in the resource-rich Midwest with
30,000 miles of tracks
laid by 1860. The cost of moving farm produces and manufactured
goods over long distances fell by 95% between 1815 and 1860. This
underlined the capacity of the rail system to answer the needs
of the national economy and insured a subsequent rapid phase of
expansion.

Growth (1860-1915). As the advantages of rail
transportation became widely acknowledged, a massive phase of
growth ensued with rail achieving dominance over the road and
waterway modes. One priority was the construction of a
transcontinental line linking the East and the West coasts,
which was completed in 1869. From that point, numerous branches
and trunks were constructed leading to an interconnected
national rail system. A standard gauge of 1.4351 meters was also
agreed upon (in 1860, 23 different gauges were still in use).
However, there were complaints made by users stating that the rates charged
by railroad companies were high and discriminatory, particularly
because of the monopoly they had on several parts of the emerging
railway system. In response, the US Congress created the Interstate Commerce
Commission (ICC) in 1887, with the authority to regulate the rates
railroads could charge (this agency also became responsible to
collect railway data). The growing level of regulation of the
rail sector was associated with then end of its spatial growth. The extent of the rail system peaked in
1916 with 254,000 road-miles.

Maturity (1915-1950). This period marked the age of rail
transportation dominance as by 1930, the 250,000 miles rail network
accounted for about 65% of all the freight tonnage carried in the
United States and close to the totality of long distance
passenger transport. Rail technology was standardized and showed little
improvements in terms of speed. Competition from trucks was however
beginning to be felt, notably for short hauls. Mileage started
to slowly decline with unprofitable lines being abandoned. The Great
Depression of the 1930s marked the first significant rationalization
with an abandonment of more than 16,000 road-miles between 1930
and 1940. By 1950 the system was downsized to 224,000 road-miles.
In addition, heavy regulations from the ICC led to a standard private
sector response; lack of investments, increased accidents, reduced
punctuality and the bankruptcy of several companies.

Rationalization (1950-2000). The post World War II era
was one of intense rationalization for rail transportation. By the
1970s, the US railway system was facing serious financial difficulties;
several railway companies were going bankrupt. One of the most significant bankruptcy
was the Penn Central in 1970, which controlled more than 10,000
road-miles. The response of the Federal Government was deregulation.
In 1980, the Staggers Rail Act enabled rail companies to fix their
own rates, service levels, as well as to abandon, sell or lease
unprofitable rail segments. Between 1950 and 2000, 79,300 road-miles
were abandoned, which left the rail system with 144,500 miles of road-miles
in 2000, a mileage similar to the mid 1880s. Just between 1975 and
1980, 12,300 road-miles were abandoned. Rail transportation was
losing passengers to road and air modes,
which meant loss of revenue and the abandonment of numerous passengers
services. The role of rail as a mean for long distance passenger
travel was collapsing. While there were about 2,000 scheduled passenger trains per
day in 1950, this number fell to 200 in the 1990s. As a result,
rail transportation became dominantly freight oriented and the development
of intermodal transportation in the 1970s justified further rationalization
within the rail industry, mainly through mergers. Among the most
significant was the Burlington Northern / Santa Fe merger in 1995,
followed by the acquisition by Union Pacific of Southern Pacific
Railroad in 1996 and the split up of Conrail (a company created
in 1976 by the Federal Government to consolidate the assets of bankrupt
rail companies) between Norfolk Southern and CSX in 1999. Freight
rates were cut in half. While in 1960, there were 106 Class I rail
operators, this figure dropped to 7 in 2002 and
remained as such
until then.

Resurgence (2000-). As of the beginning of the 21st century,
rationalization appears to be completed, leaving a more efficient
rail system based on high capacity long distance corridors connecting
major maritime gateways and inland terminals. These corridors are
almost all double-tracked. Additionally, rail freight has faced
a surge in demand linked with globalization, a level of de-industrialization
of the North American economy, as well as rising energy prices making
rail more competitive. The three most important factors behind the
recent growth of rail traffic involve a growth of international
containerized trade, growing quantities of utility coal being shipped
to power plants (namely from the Powder River Basin) and the growth
of Mexican trade. A new wave of investments along long distance
corridors (double or triple tracking) and intermodal rail terminals
has improved the efficiency and the capacity of the system. Prospects
about the future of rail transportation appear positive. As of 2008,
the American network mileage was standing at 140,000 miles.

Over its history, statistics about the rail system were collected
by different agencies, so there is a discontinuity in information sources.
For most of the 19th century, the mileage was compiled by Poor's Manual
of Railroads of the United States (here summarized by a 1897 Rand McNally
publication). Then, the Interstate Commerce Commission assumed the responsibility
between 1890 and 1977. With deregulation in 1980, the Association of
American Railroads took over the compilation of various rail statistics.